Institute first-aid kit found on a 2000-year-old shipwreck has provided a remarkable insight into the medicines concocted by ancient physicians to cure sailors of dysentery and other ailments.
Medicines found inside a wooden chest included pills made of ground-up vegetables, herbs and plants such as celery, onions, carrots, cabbage, alfalfa and chestnuts - all ingredients referred to in classical medical texts.
The tablets, which have miraculously survived being under water for more than two millennia, also contain extracts of parsley, nasturtium, radish, yarrow and hibiscus.
They were found in 136 tin-lined wooden vials on a 15m-long trading ship which was wrecked about 130BC off the coast of Tuscany.
Scientists believe they would have been used to treat gastrointestinal complaints suffered by sailors such as dysentery and diarrhoea.
"It's a spectacular find. They were very well sealed," said Dr Alain Touwaide, from the Smithsonian Conservation Biology Institute in Washington DC.
"The plants and vegetables were probably crushed with a mortar and pestle - we could still see the fibres in the tablets. They also contained clay, which even today is used to treat gastrointestinal problems."
The pills are the oldest-known archaeological remains of ancient pharmaceuticals.
They would have been taken with a mouthful of wine or water, or may have been dissolved and smeared on skin to treat inflammation and cuts.
Historians believe the presence of the medicine chest suggests that the ship may have had a doctor on board, or at least someone trained in rudimentary first aid.
The chest also contained spatulas, suction cups and a mortar and pestle.
The vessel was transporting amphorae of wine, glassware, ceramics and oil lamps when it sank in 18m of water between the Italian mainland and the island of Elbe.
"We still don't know whether it was Roman or Greek or Phoenician, nor do we know whether it was a long-distance trading ship operating throughout the Mediterranean or a coastal vessel," said Touwaide.
He said the discovery showed that medical knowledge contained in ancient Greek texts, and later in the writings of Roman scholars such as Pliny, was being put into practise in the Roman Empire.
The ship was discovered off the port of Piombino in 1974 and the wooden medicine box was found in 1989, but it is only now that scientists have been able to use DNA-sequencing technology to analyse the contents of the pills.
Gino Fornaciari, a paleo-pathologist from Pisa University, said: "As well as understanding
how the ancient Romans treated
each other, we are learning more about what illnesses they suffered from."